> How is the quorum information located on the system disk of each node kept in synch?

The server cluster infrastructure ensures that all changes are replicated and updated on all members in a cluster.

> Can this method be used to replicate application data as well?

No, that is not possible in this version of clustering. Only Quorum information is replicated and maintained in a synchronized state by the clustering infrastructure.

> Can I convert a standard cluster to an MNS cluster?

Yes. You can use Cluster Administrator to create a new Majority Node Set resource and then, on the cluster properties sheet Quorum tab, change the quorum to that Majority Node Set resource.

> What is the difference between a geographically dispersed cluster and an MNS cluster?

A geographic cluster refers to a cluster that has nodes in multiple locations, while an MNS-based cluster refers to the type of quorum resources in use. A geographic cluster can use either a shared disk or MNS quorum resource, while an MNS-based cluster can be located in a single site, or span multiple sites.

There is nothing inherent in the MNS architecture that requires any special hardware, other than what is required for a standard cluster (for example, there must be on the Microsoft Cluster HCL). However, some situations that use an MNS cluster may have unique requirements (such as geographic clusters), where data must be replicated in real time between sites.

> Does a cluster aware application need to be rewritten to support MNS?

No, using an MNS quorum requires no change to the application. However, some cluster aware applications expect a shared disk (for example SQL Server 2000), so while you do not need shared disks for the quorum, you do need shared disks for the application.

> Does MNS get rid of the need for shared disks?

It depends on the application. For example, clustered SQL Server 2000 requires shared disk for data. Remember, MNS only removes the need for a shared disk quorum.

> What does a failover cluster do in Windows Server 2008 ?
A failover cluster is a group of independent computers that work together to increase the availability of applications and services. The clustered servers (called nodes) are connected by physical cables and by software. If one of the cluster nodes fails, another node begins to provide service (a process known as failover). Users experience a minimum of disruptions in service.

> What new functionality does failover clustering provide in Windows Server 2008 ?
New validation feature. With this feature, you can check that your system, storage, and network configuration is suitable for a cluster.

Support for GUID partition table (GPT) disks in cluster storage. GPT disks can have partitions larger than two terabytes and have built-in redundancy in the way partition information is stored, unlike master boot record (MBR) disks.

> What is Dynamic quorum in Windows Server 2012 ?
Gives the administrator the ability to automatically manage the quorum vote assignment for a node, based on the state of the node. When a node shuts down or crashes, the node loses its quorum vote. When a node successfully rejoins the cluster, it regains its quorum vote. By dynamically adjusting the assignment of quorum votes, the cluster can increase or decrease the number of quorum votes that are required to keep running. This enables the cluster to maintain availability during sequential node failures or shutdowns.

> What happens to a running Cluster if the quorum disk fails in Windows Server 2003 Cluster ?
In Windows Server 2003, the Quorum disk resource is required for the Cluster
to function. In your example, if the Quorum disk suddenly became unavailable
to the cluster then both nodes would immediately fail and not be able to
restart the clussvc.

In that light, the Quorum disk was a single point of failure in a Microsoft
Cluster implementation. However, it was usually a fairly quick workaround to
get the cluster back up and operational. There are generally two solutions
to that type of problem.

1. Detemrine why the Quorum disk failed and repair.
2. Reprovision a new LUN, present it to the cluster, assign it a drive
letter and format. Then start one node with the /FQ switch and through
cluadmin designate the new disk resource as the Quorum. Then stop and
restart the clussvc normally and then bring online the second node.

> What happens to a running Cluster if the quorum disk fails in Windows Server 2008 Cluster ?

Cluster continue to work but failover will not happen in case of any other failure in the active node.

> What is Cluster-Aware Updating in Windows Server 2012 ?

Cluster-Aware Updating (CAU) is an automated feature that allows updates to be applied automatically to the host operating system or other system components in clustered servers, while maintaining availability during the update process. This feature leverages automated draining and failback of each node during the update process. By default, it uses the Windows Update Agent infrastructure as its update source.